<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>calculate</title>

    <link href="calculate.css" rel="stylesheet" type="text/css">
    <script src="calculate.js"></script>
   
    <div id="outer">
        <div  id="top">
            <span id="red">●</span>
            <span id="blue">●</span>
            <span id="yellow">●</span>
        </div>
        <div id="middle"></div>
        <div id="bottom">
            
                <div onclick=delall()>AC</div>
                <div onclick="clickbutton('+/-')">+/-</div>
                <div onclick="clickbutton('%')">%</div>
                <div onclick="clickbutton('/')">÷</div>
            
            
                <div onclick="clickbutton('7')">7</div>
                <div onclick="clickbutton('8')">8</div>
                <div onclick="clickbutton('9')">9</div>
                <div onclick="clickbutton('*')">×</div>
            
            
                <div onclick="clickbutton('4')">4</div>
                <div onclick="clickbutton('5')">5</div>
                <div onclick="clickbutton('6')">6</div>
                <div onclick="clickbutton('-')">-</div>
            
            
                <div onclick="clickbutton('1')">1</div>
                <div onclick="clickbutton('2')">2</div>
                <div onclick="clickbutton('3')">3</div>
                <div onclick="clickbutton('+')">+</div>
            
            
                <div onclick="clickbutton('0')">0</div>
                <div onclick=back()>DEL</div>
                <div onclick="clickbutton('.')">.</div>
                <div onclick=calc()>=</div>
            
        </div>
    </div>
</body>
</html>